


the endlessness that you fear

by rikacain



Category: Undertale (Video Game)
Genre: Genocide Route
Language: English
Status: Completed
Published: 2016-02-07
Updated: 2016-02-07
Packaged: 2018-05-18 22:13:07
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,600
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5945056
Author URL: https://archiveofourown.org/users/rikacain/pseuds/rikacain
Summary: <blockquote class="userstuff">
              <p>desperation and despair, at the end of the world.</p>
            </blockquote>





	the endlessness that you fear

**Author's Note:**

> alternatively, why sans fights you only when you have killed everyone and everything and nothing less than that.
> 
> (talk meta and characterisation to me, come on)
> 
> credits to [Queen of Aces](http://archiveofourown.org/users/QueenOfAces) and [lakesandquarries](http://archiveofourown.org/users/lakesandquarries) for their betaing efforts

Mettaton is dead.

Alphys lets out a strangled gasp as the metal body crumbles into pieces, with no more soul to control its movements. Sans knows that the two of them were friends, vaguely remembering a ghost with big dreams and no means to achieve it, but that was all gone.  The robot is dead.

“We have to evacuate,” Alphys finally forces out. He’d thought she would cry - but perhaps she has no more tears left. Not after Undyne. “W-we have to make sure that the- the human won’t be able to find us. Protect whoever’s left."

“you do that,” Sans says, staring at the screen and watching the… thing make its way to the elevator. It wasn’t human, and would never be. “i’ve a job to do."

“Sans,” Alphys starts, and he turns to look at her. He knows that she knows what he’s going to do; it’s clear from the way that she looks at his face and the way despair creeps slowly and insidiously across her countenance. She makes to reach out to him, perhaps even to stop him, but then withdraws abruptly, straightening up.

_ she looks better confident _ , Sans thinks idly.  The price she had to pay for it, however, was far too steep.

“We’ll be d-down below,” she says. “I’ll see you after you’re done - after you’ve got what you need.” She smiles, a mere shadow of her former nervous grin, resignation miring its hope.

She knows yet she still tries. Sans can never hope to be as determined as she is.

So he nods. “I’ll be right behind you,” he lies, and she nods back. One final act before the curtain falls, he can give her that much.

“I’ll keep the door open,” she promises.

(This is also a lie.)

* * *

He’s seen how it fights.

He’s kept track over its journey to New Home, has seen how it mercilessly slaughters everyone in its way. He’s also seen how it dodges each attack almost flawlessly, as if it was a choreographed dance; how its face twists in irritation as monsters tried to talk to it, like it has heard everything before.

How it breathed out a sigh of satisfaction, sharp and smug, when Undyne finally melted away.

It was Undyne’s fight that gave it away. Undyne is - was - a fierce warrior who trained everyday, as well as Captain of the Royal Guard. You didn’t get up there without being capable, and she was more than capable. He’d seen her spar with Papyrus (and something vicious _grabs_ at his soul, twisting it sharply), heard how she lost her eye.

It's weak and scrawny and managed to stay alive. Either it was very lucky, or something was fishy.

(The pun isn’t funny anymore - but nothing has been funny, not for a while now.)

With all the clues, Sans is more than certain that the thing is the anomaly, the one causing the jumping. More importantly, it was causing the endings. Entire blips of data, ones that represented another timeline with another Sans and Papyrus and the entire Underground, all gone. He remembers monitoring the first timeline that had disappeared and the resulting panic as his team scrambled to fix what they would later find was not a defect.

What happens when a timeline is erased, a reality erased? And if it was, could it be reversed?

That timeline had never come back. None of them ever did.

Perhaps Mettaton was right in his last moment of insight. Would it merely stop at Asgore, after it crossed the barrier and out into the human world? Or perhaps it would take a knife to the next human it crossed...

Or it wouldn’t have to, Sans realises. If it could manipulate the timeline - with  sufficient LOVE could the anomaly kill the timeline?

An entire reality erased. Irreversible.

Something heavy and thick settles down in his non-existent gut, pulling down and down and down. Could he let the destruction of his own reality rest on his conscience? Could he let them past where he would have judged them, to their supposed freedom when they might just go right on to kill this world…?

But he made a promise, his mind reminds him. A promise was a promise.

 _Promise me you’ll look after them_ , the lady behind the door had begged. _Promise me_.

And he had, even though the last promise he made was to someone long gone. He looked at them as they stabbed and clubbed and left dust in their wake, looked as they hunted monsters down just to kill them with the imitation of a smile, and he looked as they killed Papyrus when his brother tried to accept them with open arms.

She was probably dead too, that lady. Sentiment and kindness wouldn’t spare Papyrus - why would it spare her?

He could let Asgore deal with them, he tries to rationalise. The king was powerful, the most powerful in the Underground as someone who had survived the war. His prowess with his trident was legendary, his mastery of fire magic almost unmatched. Surely he could hold his own against a human that powerful.

But Asgore was also too soft, too kind-hearted. He might not even recognise the anomaly as a human. His guard would be down, and all it would take was one hit full of LOVE. That’s how strong it had gotten.

Then he would have to dodge, Sans thinks, but who in the Underground would dodge? The system of fighting was so rigid, no monster would do something so blatantly wrong. To dodge was denying your opponent a fair chance; but it didn’t deserve a fair chance, not with its powers to rewind time over and over, until the outcome it wanted appeared.

Asgore wouldn’t dodge. The world wouldn’t survive. There was no way to win, but giving up isn't an option either.

It has to be him. No one else understood, and no one else would flout the rules.

Sans stared down at his feet, unseeing.

It has to be him.

(A whisper. _Promise me_.)

He takes in a shuddering breath, and steps through a shortcut.

* * *

To destroy its determination, the only thing to do is to convince it that there is no way to win.

(The irony of how great he is at giving up doesn’t escape him. He’s been doing it for a long, long time.)

He couldn’t make it stay dead; it would merely reset the timeline, and he would fight them again and again, an endlessly repeating 'first time'. He couldn’t take away its powers. The only choice he has left is to convince it to willingly not use their powers, and at this point in time, that is to convince it that this path in this timeline ends with him.

He’d have to make the first attack, before it could land a hit on him. Normally, the initiator of a fight would give the other a sporting chance, but he supposes that the anomaly is the initiator, with its genocidal intent. A relentless attack to give a taste of what will come after, if it survives - no .

It won’t survive. That’s the idea here. Sans himself wasn’t cut out for long, drawn out battles; he has entirely too little stamina for that. The battle had to end as quickly as it can.

Gravity first, he decides. Turn it blue and drag it down to the ground where a field of bones could pierce them through. Another barrage of bones, and since he was pulling out all the stops - the gaster blasters would come in handy.

(The word - no, name - always trips on his tongue. Gaster, Gaster, Gaster. _Don't forget_ , but is this really the way he'd want to remember him by?)

More gravity. More bones. More flouting the rules of the battle system they're probably used to. More ways to dissuade them from ever coming down this path, ever again.

He's planning a murder, Sans realises numbly after he has planned several teleportations into his barrage to throw them off their feet. What would Papyrus think of him now?

He tries to cut that train of thought off before it could derail him, but Papyrus is clouding his mind. Papyrus, who would believe in anyone and in any scraps of goodness he could find within, and he had believed in them. Perhaps Sans could show them mercy, convince them that there was more to life than killing monsters...

But where would that go? They were a time traveller, able to discover every variation of every action they could take. They'd probably take his mercy, rewind, and throw it back into his face like they did to Papyrus. Papyrus, who they had ultimately killed. Maybe in another timeline they had spared his brother, just to see what he'd say.

God, it's almost like a game, isn't it? It probably is one to them.

He's their judge, jury, and executioner. Mercy is out of the question. He would offer it, just to show them what betrayal feels like.

(He has a feeling they won't take it anyway.)

So many promises broken, at the end of the world. So many people he will and has disappointed.

So very bitter, the taste of defeat and regret.

* * *

The tiny patter of feet on the marble floor. The deafening silence where there would have been the bustle of a thriving city. The ugly twist of pure loathing and frustration on its countenance as he steps out of the shadows of the golden hall.

Heh. How many times has he done this?

"let's get to the point."

 

**Author's Note:**

> *welp. i'm going to grillby's.
> 
> *papyrus, do you want anything?


End file.
